﻿#define _CRT_SECURE_NO_WARNINGS 1

// 源码中pair⽀持的<重载实现
template <class T1, class T2>
bool operator< (const pair<T1, T2>& lhs, const pair<T1, T2>& rhs)
{
	return lhs.first < rhs.first || (!(rhs.first < lhs.first) &&
		lhs.second < rhs.second);
}

// Mymap.h
namespace bit
{
	template<class K, class V>
	class map
	{
		struct MapKeyOfT//返回first
		{
			const K& operator()(const pair<K, V>& kv)
			{
				return kv.first;
			}
		};
	public:
		bool insert(const pair<K, V>& kv)
		{
			return _t.Insert(kv);
		}
	private:
		RBTree<K, pair<K, V>, MapKeyOfT> _t;
	};
}

// Myset.h
namespace bit
{
	template<class K>
	class set
	{
		struct SetKeyOfT
		{
			const K& operator()(const K& key)
			{
				return key;
			}
		};
	public:
		bool insert(const K& key)
		{
			return _t.Insert(key);
		}
	private:
		RBTree<K, K, SetKeyOfT> _t;
	};
}

// RBTree.h
enum Colour
{
	RED,
	BLACK
};
template<class T>
struct RBTreeNode
{
	T _data;
	RBTreeNode<T>* _left;
	RBTreeNode<T>* _right;
	RBTreeNode<T>* _parent;
	Colour _col;
	RBTreeNode(const T& data)
		: _data(data)
		, _left(nullptr)
		, _right(nullptr)
		, _parent(nullptr)
	{}
};

// 实现步骤：
// 1、实现红黑树
// 2、封装map和set框架，解决KeyOfT
// 3、iterator
// 4、const_iterator
// 5、key不支持修改的问题
// 6、operator[]

template<class K, class T, class KeyOfT>
class RBTree
{
private:
	typedef RBTreeNode<T> Node;
	Node* _root = nullptr;
public:
	bool Insert(const T& data)
	{
		if (_root == nullptr)
		{
			_root = new Node(data);
			_root->_col = BLACK;
			return true;
		}
		KeyOfT kot;
		Node* parent = nullptr;
		Node* cur = _root;
		while (cur)
		{
			if (kot(cur->_data) < kot(data))
			{
				parent = cur;
				cur = cur->_right;
			}
			else if (kot(cur->_data) > kot(data))
			{
				parent = cur;
				cur = cur->_left;
			}
			else
			{
				return false;
			}
		}
		cur = new Node(data);
		Node* newnode = cur;//因为cur会随着颜色的更新而移动，需要记录一下
		// 新增结点。颜色给红色
		cur->_col = RED;
		if (kot(parent->_data) < kot(data))
		{
			parent->_right = cur;
		}
		else
		{
			parent->_left = cur;
		}
		cur->_parent = parent;
		//...
		return true;
	}
}

struct __rb_tree_base_iterator
{
	typedef __rb_tree_node_base::base_ptr base_ptr;
	base_ptr node;
	void increment()
	{
		if (node->right != 0) {
			node = node->right;
			while (node->left != 0)
				node = node->left;
		}
		else {
			base_ptr y = node->parent;
			while (node == y->right) {
				node = y;
				y = y->parent;
			}
			if (node->right != y)
				node = y;
		}
	}
	void decrement()
	{
		if (node->color == __rb_tree_red &&
			node->parent->parent == node)
			node = node->right;
		else if (node->left != 0) {
			base_ptr y = node->left;
			while (y->right != 0)
				y = y->right;
			node = y;
		}
		else {
			base_ptr y = node->parent;
			while (node == y->left) {
				node = y;
				y = y->parent;
			}
			node = y;
		}
	}
};

//template <class Value, class Ref, class Ptr>
//struct __rb_tree_iterator : public __rb_tree_base_iterator
//{
//	typedef Value value_type;
//	typedef Ref reference;
//	typedef Ptr pointer;
//	typedef __rb_tree_iterator<Value, Value&, Value*> iterator;
//	__rb_tree_iterator() {}
//	__rb_tree_iterator(link_type x) { node = x; }
//	__rb_tree_iterator(const iterator& it) { node = it.node; }
//	reference operator*() const { return link_type(node)->value_field; }
//#ifndef __SGI_STL_NO_ARROW_OPERATOR
//	pointer operator->() const { return &(operator*()); }
//#endif /* __SGI_STL_NO_ARROW_OPERATOR */
//	self& operator++() { increment(); return *this; }
//	self& operator--() { decrement(); return *this; }
//	inline bool operator==(const __rb_tree_base_iterator& x,
//		const __rb_tree_base_iterator& y) {
//		return x.node == y.node;
//	}
//	inline bool operator!=(const __rb_tree_base_iterator& x,
//		const __rb_tree_base_iterator& y) {
//		return x.node != y.node;
//}
//


#include"RBTree.h"
namespace zyb
{
	template<class K>
	class set
	{
		struct SetKeyOfT
		{
			const K& operator()(const K& key)
			{
				return key;
			}
		};
	public:
		typedef typename RBTree<K, const K, SetKeyOfT>::Iterator iterator;
		typedef typename RBTree<K, const K, SetKeyOfT>::ConstIterator
			const_iterator;
		iterator begin()
		{
			return _t.Begin();
		}
		iterator end()
		{
			return _t.End();
		}
		const_iterator begin() const
		{
			return _t.Begin();
		}
		const_iterator end() const
		{
			return _t.End();
		}
		pair<iterator, bool> insert(const K& key)
		{
			return _t.Insert(key);
		}
		iterator find(const K& key)
		{
			return _t.Find(key);
		}
	private:
		RBTree<K, const K, SetKeyOfT> _t;
	};
	void Print(const set<int>& s)
	{
		set<int>::const_iterator it = s.end();
		while (it != s.begin())
		{
			--it;
			// 不⽀持修改
			//*it += 2;
			cout << *it << " ";
		}
		cout << endl;
	}
	void test_set()
	{
		set<int> s;
		int a[] = { 4, 2, 6, 1, 3, 5, 15, 7, 16, 14 };
		for (auto e : a)
		{
			s.insert(e);
		}
		for (auto e : s)
		{
			cout << e << " ";
		}
		cout << endl;
		Print(s);
	}
}

#include"RBTree.h
namespace zyb
{
	template<class K, class V>
	class map
	{
		struct MapKeyOfT
		{
			const K& operator()(const pair<K, V>& kv)
			{
				return kv.first;
			}
		};
	public:
		typedef typename RBTree<K, pair<const K, V>, MapKeyOfT>::Iterator
			iterator;
		typedef typename RBTree<K, pair<const K, V>, MapKeyOfT>::ConstIterator
			const_iterator;
		iterator begin()
		{
			return _t.Begin();
		}
		iterator end()
		{
			return _t.End();
		}
		const_iterator begin() const
		{
			return _t.Begin();
		}
		const_iterator end() const
		{
			return _t.End();
		}
		pair<iterator, bool> insert(const pair<K, V>& kv)
		{
			return _t.Insert(kv);
		}
		iterator find(const K& key)
		{
			return _t.Find(key);
		}
		V& operator[](const K& key)
		{
			pair<iterator, bool> ret = insert(make_pair(key, V()));
			return ret.first->second;
		}
	private:
		RBTree<K, pair<const K, V>, MapKeyOfT> _t;
	};

	//测试代码
	void test_map()
	{
		map<string, string> dict;
		dict.insert({ "sort", "排序" });
		dict.insert({ "left", "左边" });
		dict.insert({ "right", "右边" });
		dict["left"] = "左边，剩余";
		dict["insert"] = "插⼊";
		dict["string"];
		map<string, string>::iterator it = dict.begin();
		while (it != dict.end())
		{
			// 不能修改first，可以修改second
			//it->first += 'x';
			it->second += 'x';
			cout << it->first << ":" << it->second << endl;
			++it;
		}
		cout << endl;
	}
}

enum Colour
{
	RED,
	BLACK
};
template<class T>
struct RBTreeNode
{
	T _data;
	RBTreeNode<T>* _left;
	RBTreeNode<T>* _right;
	RBTreeNode<T>* _parent;
	Colour _col;
	RBTreeNode(const T& data)
		: _data(data)
		, _left(nullptr)
		, _right(nullptr)
		, _parent(nullptr)
	{}
};
template<class T, class Ref, class Ptr>
struct RBTreeIterator
{
	typedef RBTreeNode<T> Node;
	typedef RBTreeIterator<T, Ref, Ptr> Self;
	Node* _node;
	Node* _root;
	RBTreeIterator(Node* node, Node* root)
		:_node(node)
		, _root(root)
	{}
	Self& operator++()
	{
		if (_node->_right)
		{
			// 右不为空，右子树最左结点就是中序第一个
			Node* leftMost = _node->_right;
			while (leftMost->_left)
			{
				leftMost = leftMost->_left;
			}
			_node = leftMost;
		}
		else
		{
			// 孩⼦是父亲左的那个祖先
			Node* cur = _node;
			Node* parent = cur->_parent;
			while (parent && cur == parent->_right)
			{
				cur = parent;
				parent = cur->_parent;
			}
			_node = parent;
		}
		return *this;
	}
	Self& operator--()
	{
		if (_node == nullptr) // end()
		{
			// --end()，特殊处理，走到中序最后一个结点，整棵树的最右结点
			Node* rightMost = _root;
			while (rightMost && rightMost->_right)
			{
				rightMost = rightMost->_right;
			}
			_node = rightMost;
		}
		else if (_node->_left)
		{
			// 左子树不为空，中序左子树最后一个
			Node* rightMost = _node->_left;
			while (rightMost->_right)
			{
				rightMost = rightMost->_right;
			}
			_node = rightMost;
		}
		else
		{
			// 孩子是父亲右的那个祖先
			Node* cur = _node;
			Node* parent = cur->_parent;
			while (parent && cur == parent->_left)
			{
				cur = parent;
				parent = cur->_parent;
			}
			_node = parent;
		}
		return *this;
	}
	Ref operator*()
	{
		return _node->_data;
	}
	Ptr operator->()
	{
		return &_node->_data;
	}
	bool operator!= (const Self& s) const
	{
		return _node != s._node;
	}
	bool operator== (const Self& s) const
	{
		return _node == s._node;
	}
};
template<class K, class T, class KeyOfT>
class RBTree
{
	typedef RBTreeNode<T> Node;
public:
	typedef RBTreeIterator<T, T&, T*> Iterator;
	typedef RBTreeIterator<T, const T&, const T*> ConstIterator;
	Iterator Begin()
	{
		Node* leftMost = _root;
		while (leftMost && leftMost->_left)
		{
			leftMost = leftMost->_left;
		}
		return Iterator(leftMost, _root);
	}
	Iterator End()
	{
		return Iterator(nullptr, _root);
	}
	ConstIterator Begin() const
	{
		Node* leftMost = _root;
		while (leftMost && leftMost->_left)
		{
			leftMost = leftMost->_left;
		}
		return ConstIterator(leftMost, _root);
	}
	ConstIterator End() const
	{
		return ConstIterator(nullptr, _root);
	}
	RBTree() = default;
	~RBTree()
	{
		Destroy(_root);
		_root = nullptr;
	}
	pair<Iterator, bool> Insert(const T & data)
	{
		if (_root == nullptr)
		{
			_root = new Node(data);
			_root->_col = BLACK;
			return make_pair(Iterator(_root, _root), true);
		}
		KeyOfT kot;
		Node* parent = nullptr;
		Node* cur = _root;
		while (cur)
		{
			if (kot(cur->_data) < kot(data))
			{
				parent = cur;
				cur = cur->_right;
			}
			else if (kot(cur->_data) > kot(data))
			{
				parent = cur;
				cur = cur->_left;
			}
			else
			{
				return make_pair(Iterator(cur, _root), false);
			}
		}
		cur = new Node(data);
		Node* newnode = cur;
		cur->_col = RED;
		if (kot(parent->_data) < kot(data))
		{
			parent->_right = cur;
		}
		else
		{
			parent->_left = cur;
		}
		cur->_parent = parent;
		while (parent && parent->_col == RED)
		{
			Node* grandfather = parent->_parent;

			if (parent == grandfather->_left)
			{
				Node* uncle = grandfather->_right;
				if (uncle && uncle->_col == RED)
				{
					parent->_col = uncle->_col = BLACK;
					grandfather->_col = RED;
					cur = grandfather;
					parent = cur->_parent;
				}
				else
				{
					if (cur == parent->_left)
					{
						RotateR(grandfather);
						parent->_col = BLACK;
						grandfather->_col = RED;
					}
					else
					{
						RotateL(parent);
						RotateR(grandfather);
						cur->_col = BLACK;
						grandfather->_col = RED;
					}
					break;
				}
			}
			else
			{
				Node* uncle = grandfather->_left;
				if (uncle && uncle->_col == RED)
				{
					parent->_col = uncle->_col = BLACK;
					grandfather->_col = RED;
					cur = grandfather;
					parent = cur->_parent;
				}
				else 
				{
					if (cur == parent->_right)
					{
						RotateL(grandfather);
						parent->_col = BLACK;
						grandfather->_col = RED;
					}
					else
					{
						RotateR(parent);
						RotateL(grandfather);
						cur->_col = BLACK;
						grandfather->_col = RED;
					}
					break;
				}
			}
		}
		_root->_col = BLACK;
		return make_pair(Iterator(newnode, _root), true);
}
Iterator Find(const K& key)
{
	Node* cur = _root;
	while (cur)
	{
		if (cur->_kv.first < key)
		{
			cur = cur->_right;
		}
		else if (cur->_kv.first > key)
		{
			cur = cur->_left;
		}
		else
		{
			return Iterator(cur, _root);
		}
	}
	return End();
}
private:
	void RotateL(Node* parent)
	{
		Node* subR = parent->_right;
		Node* subRL = subR->_left;
		parent->_right = subRL;
		if (subRL)
			subRL->_parent = parent;
		Node* parentParent = parent->_parent;
		subR->_left = parent;
		parent->_parent = subR;
		if (parentParent == nullptr)
		{
			_root = subR;
			subR->_parent = nullptr;
		}
		else
		{
			if (parent == parentParent->_left)
			{
				parentParent->_left = subR;
			}
			else
			{
				parentParent->_right = subR;
			}
			subR->_parent = parentParent;
		}
	}
	void RotateR(Node* parent)
	{
		Node* subL = parent->_left;
		Node* subLR = subL->_right;
		parent->_left = subLR;
		if (subLR)
			subLR->_parent = parent;
		Node* parentParent = parent->_parent;
		subL->_right = parent;
		parent->_parent = subL;
		if (parentParent == nullptr)
		{
			_root = subL;
			subL->_parent = nullptr;
		}
		else
		{
			if (parent == parentParent->_left)
			{
				parentParent->_left = subL;
			}
			else
			{
				parentParent->_right = subL;
			}
			subL->_parent = parentParent;
		}
	}
	void Destroy(Node* root)
	{
		if (root == nullptr)
			return;
		Destroy(root->_left);
		Destroy(root->_right);
		delete root;
	}
private:
	Node* _root = nullptr;
};